This invention relates to clothes washing machines and, more particularly, to a simplified construction for small and conventional size washing machines which provides vibration damping during its spin cycle when the tub rotates at high speed. The invention combines a vibration damping means for supporting the entire washing machine together with a centrifugally operated balance seeking water retention means on the clothes receiving tub or spin basket. Also, the simplified construction of the invention allows the tub and the outer casing of the washing machine to be formed of injection molded plastic material. Therefore, the cost of manufacture of the invention is lower than in known washing machines of like sizes and capacity.
Heretofore known washing machines have utilized various means for stabilizing the structure during its operation. Washing machines tend to become most unstable during the spin cycle wherein the oscillating motion of the tub is changed to a rotating motion for extracting water therefrom. During this spin cycle, the clothes inside the tub are commonly in random position around the center of tub rotation. An imbalance is then created during rotation which, if not compensated for, results in severe vibration of the entire washer.
Known vibration damping means for washing machine spin cycles include a water retaining ring surrounding the outside of the clothes receiving tub. This water retaining ring receives water which is centrifuged from the tub during the spin cycle and retains the water therein due to the same centrifugal action. The retained water provides a heavy mass positioned farther away from the axis of rotation than any other portion of the tub. This large liquid mass seeks a position in the ring which tends to compensate for the imbalance in the rotating tub thereby lessening the vibration. As the spin cycle of the washing machine is completed and the tub rotation slows, the fluid mass, at a critical speed, ceases to be retained against the outer ring wall and exits the ring through an open bottom therein. Heretofore known water retaining rings have been of expensive metal fabrication. Applicant's spin basket and outer ring may be made of two pieces of injection molded plastic.
To further dampen imbalance caused by randomly positioned clothes in the spinning tub, known washing machines have utilized structure including shock absorbers mounted around a floating interior frame inside the washing machine casing whereby substantially the entire interior frame, motor, driving engagement, and tub are floatingly positioned inside the outer washing machine casing. While this structure damps the vibration caused during an imbalanced spin cycle, its complexity and cost of manufacture is high. A need has therefore arisen for a washing machine of simplified low cost construction embodying a molded spin basket with centrifugal water retaining ring and a machine support means which provides vibration damping characteristics equal to or superior than presently known in washing machines.